Fuel tanks may be utilized in vehicle systems for storing fuel to be used during combustion in an engine of the vehicle system. During vehicle operation, fuel may be displaced within the fuel tank due to changes in velocity of the vehicle, such as during cornering, braking, and acceleration. When displaced, fuel may impact walls of the tank and generate noise. Noise produced by these impacts may be more apparent with hybrid vehicles, since they may operate with minimal interior noise when fuel combustion is deactivated. As such, liquid fuel tanks for automotive vehicles are designed with various constructions to reduce noise, vibration and ride harshness generated by the motion of fuel within the fuel tank.
For example, U.S. Pat. No. 5,850,933 discloses a fuel tank including one or more baffles, which extend between opposite ends of the tank so as to restrict fuel flow within the tank. As such, the impact force and therefore the noise produced from fuel hitting the walls of the fuel tank may be reduced. Further, many fuel tanks comprise baffles constructed with holes, so that fuel may still flow through the baffle, but in a restricted manner. In this way, the velocity of fuel with respect to the fuel tank may be attenuated while maintaining the overall storage volume of the tank.
However, the inventors herein have recognized potential issues with such fuel tank systems. As an example, during refueling, the baffles may restrict the flow of fuel into the fuel tank. Specifically, fuel entering the fuel tank may bounce off the baffle wall and spray back towards the refueling nozzle. Thus, the baffle wall may act as a flow restriction for fuel entering the tank during refueling. Fuel entering the tank may therefore be impeded and/or confined by the baffle wall. This may result in elevated pressures and/or liquid levels on the refueling side of the baffle as compared to regions of the fuel tank on the opposite side of the baffle. As such, the fuel pump may be shut off before the fuel tank is filled. In another example, vapor pressure in the fuel tank may increase due to the fuel bouncing off the baffle wall. Increases in the fuel tank pressure may result in corresponding rises in loading of a fuel vapor storage canister of the fuel tank system.
In one example, the issues described above may be at least partly addressed by a method for receiving a nozzle into a filler tube which may extend into a fuel tank to fuel the fuel tank, and directing fuel through said tube against vanes in a baffle which may form a compartment within said tank and during said fueling, enabling said vanes to open so that pressure within said compartment may remain below a level which may otherwise cause shut off said nozzle.
In some examples, enabling said vanes to open may comprise a mechanical release of said vanes in response to insertion of said nozzle. However, in other examples, enabling of said vanes to open may comprise an electro-mechanical release of said vanes by a relay in response to insertion of said nozzle. In still further examples enabling said vanes to open may comprise pressure exerted by said fuel acting against said vanes during said fueling which may be sufficient to overcome a weight of said vanes which may be exerting a closing force on said vanes.
In another representation, the issues described above may be at least partly addressed by a method comprising fueling a fuel tank by receiving a nozzle into a filler tube which may extend into said tank and directing fuel through said tube against vanes in a baffle which may form a compartment within said tank, where said vanes may include a plurality of holes to allow a portion of said fuel to flow therethrough. During said fueling, the method may additionally or alternatively comprise enabling said vanes to open so that pressure within said compartment may remain below a level which would otherwise cause shut off said nozzle.
In further examples, the method may comprise routing fuel vapors from said tank into a fuel vapor recovery system. In another example, the method may comprise supplying said fuel from said tank to an internal combustion engine. In yet other examples, the method may additionally or alternatively comprise periodically purging at least a portion of said fuel vapors from said tank and said fuel vapor recovery system into said engine. In some examples, internal combustion may drive a motor vehicle and said baffle may reduce sloshing of said fuel and generation of said fuel vapors while said motor vehicle is being driven.
In this way, fuel tank noise may be reduced, while the storage capacity of the fuel tank may be increased. By including baffles with adjustable vanes, the fuel tank may still offer the same sound reduction benefits of conventional fuel tank systems, while also reducing premature refueling shutoffs and fuel vapor canister loading. During refueling, the vanes may be adjusted to a first position so that fuel may flow to the extremities of the tank, relatively unrestricted. In this way, the amount of fuel impacting the baffle during refueling may be reduced. As a result, vapor pressure in the fuel tank, and canister loading may be reduced. However, after refueling, the baffles may be adjusted to a closed second position, so that movement of fuel within the fuel tank may be restricted and therefore noise produced from the fuel sloshing around in the fuel tank may be reduced.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.